Getting the Most: Part 1

Wed, June 06, 2018

[fsn_row][fsn_column width="12" column_style="light"][fsn_text] In the world of heat transfer, with close approach temperatures a little change can mean a lot of savings to the cost of equipment. Approach temperatures are critical to the sizing and selection of heat exchangers, cooling towers and other passive heat transfer equipment.  Simply stated, the approach temperature is the difference between the outlet temperature of one fluid to the inlet temperature of the other. [caption id="attachment_414" align="aligncenter" width="277"] B&G brazed plate heat exchangers[/caption] There are two approach temperatures for every heat transfer process.  In general, for a given capacity, the larger the approach, the smaller the heat exchanger. The difference between a two-degree and three-degree approach temperature for plate heat exchangers can reduce the number of plates by as much as fifty percent!  AND if you are using the heat exchanger in a condenser water application, you might find that the cooling tower is oversized and has excess capacity for the load. This means the outlet temperature from the cold-water basin of the tower could be lower than required.  Why not use that lower water temperature (wider approach) to reduce the size of the plate heat exchanger? Another useful strategy is to increase the delta-T of the condenser water at the tower to reduce the flow rate, possibly reducing the pipe size and/or pump size and horsepower. [caption id="attachment_2137" align="aligncenter" width="294"] Installation of a Marley cooling tower[/caption] All of this requires a good knowledge of the relationships between plate heat exchangers, cooling towers and pumps.  That’s where the Bornquist IDEA group comes in.  The Bornquist IDEA (Integrated Design Engineering Assistance) group is here to work with you to optimize your project to reduce energy consumption, first costs, or both! Utilizing the system knowledge from manufacturers such as Bell & Gossett pumps and heat exchangers, Marley Cooling Towers and Danfoss Variable Frequency Drives, we can help you determine how an optimized approach could work for you.  It’s just part of the service that you can and should expect from Bornquist.  After all, we’ve been doing this since 1937! Contact your Bornquist salesperson, call our office at (773) 774-2800, or e-mail us at bornquist@bornquist.com. --Mike Hultgren

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Tags: bell & gossett , cooling towers , engineering , heat exchangers , heat transfer , HVAC , plate heat exchangers